Pavement body, method for constructing pavement body, and mold form for concrete

ABSTRACT

In order to provide a pavement body that is well drained and that keeps a part of water at a time of rain so as to avoid generation of a large amount of discharging water, that supplies the kept water to a surface layer at a time of drought and that soaks up the water of the roadbed so as to lower the temperature of the surface layer, a middle layer part ( 12 ) is formed by laying a porous aggregate mixture (a) made by mixing a porous material with a solidification material of a cement system, and a surface layer part ( 11 ) is formed by laying an asphalt mixture (b) having a water permeable function on the middle layer ( 12 ) so that a base course ( 1   a ) comprising a pavement body ( 1 ) is formed.

FIELD OF THE ART

This invention relates to a pavement body, a method for constructing a pavement body, and a mold form for concrete whose water holding property and water permeable property are improved by using a porous aggregate mixture.

BACKGROUND ART

A pavement shown in the patent document 1 is known as a pavement having water holding property and water absorbing property. The pavement described in this document comprises at least a surface layer, a base course and a roadbed down from the top in this order. The surface layer having the water holding property is formed by filling the water holding cement milk that holds the water in a void of the pavement layer made of open graded asphalt of a predetermined thickness. The base course located next to the surface layer is set as a water holding base course layer whose thickness is thicker than the thickness of the surface layer and that is made of aggregate comprising countless numbers of micro bores that hold water. With this arrangement, a large amount of the water can be held by a combination of the water holding surface layer and the water holding base course layer.

In addition, for example, a pavement body shown in the patent document 2 is known as a pavement body that can produce an effect of lowering the surface temperature of the pavement.

The pavement described in this document relates to a road pavement structure where a water permeable pavement material inside of which voids are provided is laid as a pavement part of the road. The pavement part of the road pavement structure comprises a water permeable layer made of a water permeable pavement material and a water holding layer that is made of the water permeable material into which a water holding material is impregnated, and the water permeable layer or the water holding layer is dispersed toward a plain surface of the surface of the road.

PRIOR ART DOCUMENT Patent Document

-   Patent document 1: Japanese Unexamined Patent Application     Publication No. 2008-156944 -   Patent document 2: Japanese Unexamined Patent Application     Publication No. 2002-250001

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, with the arrangement of the patent document 1, in case that an amount of the water exceeds a water holding capacity, there is a problem that excessive water spills over the road surface. In addition, in case that the moisture of the held water evaporates, artificial heat thermally stored on the surface layer or solar heat is emitted so that it can be a cause of a heat island phenomenon that the outside air temperature rises.

Meanwhile, with the arrangement of the patent document 2, since the water permeable pavement member is laid on the base course part, and then the water holding slurry material is dispersed and impregnated toward the plain surface of the surface of the water permeable pavement part, an operation to pave the pavement part becomes very troublesome.

In addition, in case of an arrangement of a conventional surface drain pavement wherein the surface of the pavement inclines at the same angle from a center toward both ends in the width direction by a certain distance and the remaining distance of the surface of the pavement inclines at an angle bigger than the above-mentioned angle, there are problems such that the water exceeding the range of holding water and permeable water flows into a main sewerage at once and the water exceeding the drainage capacity might flow back to the pavement, or the overflown water becomes an obstacle for traffic of bicycles or two-wheel vehicles running on a side strip, even though the surface layer part is provided with the water holding property or the water permeable property.

A main object of this invention is to fundamentally solve the above-mentioned problems by reconsidering a raw material used for the pavement body or a structure of the pavement body.

Means to Solve the Problems

In order to attain the above object, the present claimed invention takes the following measures.

More specifically, a pavement body of this invention is characterized by comprising at least two layers, wherein a porous aggregate mixture made by mixing a porous material with a solidification material of a cement system is laid and a surface layer material having a water permeable function is laid on the porous aggregate mixture.

In accordance with this invention, since the pavement body has the water holding property and the water permeable property, it is possible to store the water on the top part of the roadbed and to soak the water into the roadbed moderately. As a result, at a time of rain, it is possible to reduce excessive water to enter into the roadbed by improving the water drainage and storing the water in the pavement body. In case that the drought continues, since the water stored in the pavement body is sucked up and furthermore the water is sucked up from the roadbed through the pavement body, temperature rise on the surface layer can be effectively prevented.

At this time, in order to adjust an amount of the water that penetrates into the roadbed without excess or deficiency, it is preferable that a semi impermeable film having both the water permeable function and a blocking property is formed on a boundary between the porous aggregate mixture and the roadbed locating under the porous aggregate mixture.

In order to introduce the excessive water to a drainage facility appropriately, it is effective that the semi impermeable film is inclined in a direction of a drain.

In order to eliminate a town ditch, it is preferable that a surface of a road pavement is formed by laying the surface layer material in a flat state from one end part in a width direction to the other end part without any cross slope from a center to each end in the width direction.

As another arrangement to realize the same object represented is that a surface of a road pavement is formed with the surface layer material having the water permeable function inclined from a center to one end part toward a width direction and the center to the other end part by a certain cross slope respectively.

In addition, in order to discharge the excessive water into the drainage facility, it is preferable that a semi impermeable film is inclined in a direction of a drain.

In order to alleviate a worried “remixing” phenomenon that the roadbed becomes muddy due to vibration from the surface layer part in a state that the rainfall infiltrates into the deepest part, it is preferable that a crushed stone base course is laid underneath the porous aggregate mixture made by mixing the porous material with the solidification material of the cement system, and furthermore a porous material without including a mixture such as a solidification material is laid underneath the crushed stone base course.

In order to make it possible to provide this invention at a low cost and also to contribute to the ecology largely by recycling the industrial waste, it is preferable that the porous material is clinker ash.

In order to lay the pavement body without excavating a roadbed of a current road, it is preferable that a current pavement is taken away so as to expose a roadbed, a middle layer part comprising the porous aggregate mixture is constructed, and a surface layer part comprising the surface layer material having the water permeable function is constructed sequentially.

In order to newly construct the pavement body effectively, it is preferable to construct a base layer part comprising a porous material without including the mixture such as the solidification material, a second middle layer part comprising the crushed stone base course, a middle layer part comprising the porous aggregate mixture, and the surface layer part comprising a surface layer material having the water permeable function sequentially from a bottom to a top.

In addition, a mold form for concrete in accordance with this invention is a porous aggregate mixture made by mixing a porous material with a solidification material of a cement system molded into a plate shape, inside of which concrete is casted and the mold form is backfilled as a part of a concrete structure.

The mold form has both the superior water permeable property and the superior water absorbing property, and the surplus water generating during casting the ready-mixed concrete is discharged outside and the water necessary for hardening the concrete is kept inside of the mold form by means of the water holding property and the water is supplied to inside of the concrete gradually in accordance with a reaction heat at a time when the concrete is hardened. With this property, it is possible to secure the hardness of the concrete structure. In addition, it is difficult to treat the bleeding water as being the strong alkali water such that the blooding water requires to be neutralized with sulfuric acid at a time of casting the concrete, however, if most part of the bleeding water is confined to inside of the mold form, it is possible to dissolve this concern.

Furthermore, the pavement body of this invention other than the above-mentioned pavement body is characterized by that a middle layer part is formed by laying a porous aggregate mixture made by mixing a porous material with a solidification material of a cement system on a concrete floor slab overhanging from a base part, and a surface layer part is formed by laying a surface layer material on the middle layer part so that a base course having a water absorbing property and a water permeable property is formed on a platform of a train.

A temperature on the platform for electric trains rises during summer due to the outside air temperature or influence from thermal storage in a train body, even though the direct sun light is shut out on the platform. However, the platform is made of the pavement body having water holding property and water permeable property, it is possible to restrain temperature rise in a surrounding area.

Effect of the Invention

As mentioned, in accordance with this invention, since the pavement body is made of the material having both the water holding property and the water permeable property so that it is possible to soak the water through the roadbed appropriately in addition to keep the water, the water is kept and soaked up at a dried time and furthermore in a case that no water is supplied to the roadbed during a long period such as drought, the water is soaked up and it is possible to deter the temperature rise on the surface layer. In addition, since the water can be absorbed at any place on the asphalt locating at the surface layer, and the water is kept at any place, it is possible to realize a well drained arrangement without forming puddles and there will be no case that a large amount of water flows into a drain at once at a time of torrential rain. Then it is possible to provide the pavement body that prevents a large amount of water from flowing in a drainage pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a pavement body in accordance with one embodiment of this invention.

FIG. 2 is a cross-sectional view showing a developed example of the pavement body to a road.

FIG. 3 is a cross-sectional view showing a pavement body in accordance with a second embodiment of this invention.

FIG. 4 is a view showing the other example to apply the pavement body of this invention.

FIG. 5 is a view showing a further different example to apply the pavement body of this invention.

FIG. 6 is a cross-sectional view showing the other example to apply the porous aggregate mixture of this invention.

FIG. 7 is a cross-sectional view showing a configuration of a conventional pavement body.

BEST MODES OF EMBODYING THE INVENTION

One embodiment of this invention will be explained with reference to drawings.

First Embodiment

FIG. 1 shows a cross-section of a pavement body (1) in accordance with this embodiment that can be applied to, so called, the L transportation {less than 100 (number of cars/day·direction)}, and furthermore the B transportation {more than or equal to 250 and less than 1000 (number of cars/day·direction)}. A middle layer part 12 comprising a porous aggregate mixture made by mixing clinker ash (CA) as a porous material with a solidification material of a cement system is laid and a surface layer part (11) comprising a material (b) having a permeable function is laid on the middle layer part 12 so that a base course 1 a is formed with the two layers; the surface layer part 11 and the middle layer part 12.

The clinker ash is contained by about 15% in a coal ash generated after finely crushed coal is burned at a high temperature (1300° C.) in a thermal plant or a steel plant. The clinker ash is burned particles that are mutually coagulated in a boiler and that fall and accumulate in a water tank of a bottom part of the boiler. And the remainder is called as fly ash. Both the clinker ash and the fly ash used to be treated on the scrap as industrial waste. Since the clinker ash has a lot of micro pores so that its surface area is big, it is very light and superior in water permeability, and superior in water holding property such that about 40% of its volume can be stored as well. Then in this embodiment, the clinker ash is used for the pavement body 1 in order to give a good water drainage property and a water suction property to the road, in addition to reutilization of resources. Since most part of a composition of the clinker ash consists of silica or alumina, the clinker ash is strong in the aggregate strength so that there is no fear in the strength after used (after added). In this embodiment used is a porous aggregate mixture (a) that is made of at least a solidification material of a cement system mixed with the clinker ash having a specific diameter among the discharged coal ash, and that is tightly hardened. A mixing ratio is, for example, 1:0.14˜0.15. Since the clinker ash is burned at a high temperature while mixing, no organic matter (a root of a plant or harmful germs) exists in the material so that it has a merit of facilitating a reaction of solidification material mixed while used (at a time of processing).

Although the fly ash also contains silica or alumina, it is in a powdery state so as to attach to a wall surface of the boiler and too fine to expect a desired water permeability and water holding property because the fly ash solidifies in a clogged state if the solidification material of the cement system is mixed. As a result, it uses the clinker ash whose particle diameter is bigger than that of the fly ash.

Since the clinker ash is superior in water permeability and water holding property, it contains water even though it is left as it is. However, if the clinker ash contains water, the clinker ash solidifies in a clogged state at a time of mixing with the solidification material of the cement system. Meanwhile, if water is short, the solidification becomes insufficient, resulting in shortage of the strength. Then it is necessary to solidify the porous aggregate mixture (a) by developing a reaction of the solidification material of the cement system without clogging while necessary water (fresh water) and an additive are added.

As a preferable embodiment, it has been verified by an experiment that it is extremely effective to use a particle size of the clinker ash as being a main material smaller than or equal to 20 mm (in this regard, the particle size of 0.074 mm or smaller occupies less than or equal to 5% of the total), the mixing ratio (a dry soil weight ratio) of the porous aggregate mixture (a) is the clinker ash as being the main material:the solidification material of the cement system=1:0.07˜0.2, and the fresh water 0.18˜0.25 and the additive (150˜200/1 dilution) are added to the porous aggregate mixture (a).

With this arrangement, it is possible to obtain a concretion of the porous aggregate mixture (a) having a necessary strength with keeping the water holding property and water permeability.

However, although the above-mentioned porous aggregate mixture (a) has the strength, it is hard to say that the porous aggregate mixture (a) as a surface layer material is enough strong to directly apply to the B transportation where heavy loaded trucks with heavy weight run. More specifically, there is still a problem in the strength such as an abrasion resistance, and in view of the particle shape of the material, in order to get rid of this problem it becomes necessary to cast a large amount of solidification material and to knead the expensive additive and also there are a lot of problems in conducting maintenance. Then in this embodiment, the base course 1 a is formed based on a totally new idea that the asphalt mixture (b) is laid as being a surface layer material on the surface layer material 11, and a middle layer part 12 comprising the porous aggregate mixture (a) using the clinker ash is arranged directly below the surface layer material 11.

The asphalt mixture (b) is a water permeable asphalt mixture whose strength is improved by mixing an aggregate into, so called, a part of a water permeable asphalt that is superior in water permeability.

In this embodiment, a thickness of the middle layer part 12 comprising the clinker ash mixture is 100˜300 mm, and a thickness of the surface layer part 11 comprising the asphalt mixture is 40˜50 mm. The total thickness of the pavement is set at generally the same as a construction thickness of a general asphalt mixture. As a result, construction of the pavement can be completed by taking away a current pavement (asphalt) so as to expose the roadbed (A), and then by constructing the middle layer part 12 and the surface layer part 11 sequentially. Then it is possible to construct the pavement by avoiding disturbing a surface of the roadbed (A) at a time of excavation without accompanying discharge of earth and sand due to excavation. It is a matter of course that a thickness of the pavement can be set at the optimal value with considering the water permeability in case of constructing a new road, and it is not always required to construct the pavement without excavation of a roadbed (A) of the current road. In case of constructing a new road, an arrangement shown in FIG. 3, to be described later, is also effective.

In addition, in this embodiment, a semi water impermeable film 13 is arranged at a boundary between the middle layer part 12 comprising the porous aggregate mixture (a) and the roadbed (A) locating below the middle layer part 12. Since the semi water impermeable film 13 uses an asphalt emulsion that can be sprayed and mixed at a normal temperature on the roadbed (A), the semi water impermeable film 13 is formed on the roadbed (A) prior to construction of the middle layer part 12 and is designed not to shut water toward the roadbed (A) completely but to penetrate water to a certain degree. Since the asphalt emulsion can be sprayed and mixed at a normal temperature, it is environmentally more friendly such as energy saving and CO₂ suppression compared with a conventional method and extremely superior in safety because a fire unlikely occurs. In addition, in case of constructing the pavement, the semi water impermeable film 13 is constructed to incline about 2˜3° in a direction of a drain (B) buried at a side of a road so as to send out the excessive water that fails to penetrate from the drain (B) to a drainage facility (C).

The pavement body 1 having the above-mentioned arrangement in accordance with this embodiment is the base course 1 a that comprises the middle layer part 12 formed by laying the porous aggregate mixture (a) made by mixing the porous material with the solidification material of the cement system and the surface layer material 11 formed by laying the asphalt mixture (b) having the water permeable function on middle layer part 12. As mentioned, since the concrete mixture (b) having the water permeable property is used for the surface layer part 11 and the porous aggregate mixture (a) is used for the middle layer part 12 just below the surface layer part 11, the base course 1 a comprising the surface layer part 11 and the middle layer part 12 has the water holding property and the water permeable property so that it is possible for the water to appropriately soak through the roadbed (A) locating below the two layers 11, 12. As a result, at a time of drying, the water held in the middle layer part 12 is sucked up through the surface layer part 11, and in case that dry weather further continues so that there is no supply of the water to the base course 1 a comprising the surface layer part 11 and the middle layer part 12, it is possible to suck the water from the roadbed (A) so that temperature rise on the surface layer part 11 can be prevented. Then, it is possible to more effectively prevent a heat island phenomenon compared with a conventional structure of the pavement body that completely blocks the water from entering the roadbed (A) so that this arrangement contributes also to reduction of CO₂ significantly.

In addition, in case that the amount of rainfall increases, since the pavement body 1 is superior in water absorption and water permeability, it is possible to absorb the water at any place of the surface layer part 11 and to keep the water at any place of the surface layer part 11. As a result, since a large amount of water will never flow into the drain (B) at once, it is possible to prevent a large amount of water from entering into a drainage facility (C) so that it is extremely effective as countermeasures against disaster such as a flood in an urban area or soil avalanche due to slope collapse. For the pavement body 1, in case that the amount of the rainfall per hour is about 70 mm, surface drainage is not necessary and the water penetrates inside of the pavement body 1 and furthermore the roadbed (A) and it is possible for the clinker ash to keep the water more than or equal to 40% of its volume. In case that the amount of the rainfall exceeds a certain amount, since the excessive rainfall can be discharged through the drains (B) arranged at certain intervals, it is possible to effectively reduce a possibility of remaining the water such as a puddle on the surface layer part 11.

In addition, since the pavement body 1 of this embodiment forms the semi water impermeable film 13 having both the water permeable function and the blocking function at the boundary between the middle layer part 12 comprising the porous aggregate mixture (a) and the roadbed (A) locating below the middle layer part 12, it is possible to appropriately adjust the excessive water over the roadbed (A) or ill water drainage of the base course 1 a.

Especially, since the semi water impermeable film 13 is inclined in a direction of the drains (B), if the excessive water is arranged to flow into the drainage facility (C), after an appropriate amount of the water permeates into the roadbed (A), the surplus water flows smoothly to the direction of the drains (B) along the inclination of the semi water impermeable film 13. As a result, no water remains on the surface layer part 11 and a part of the water soaks into the roadbed (A) and further excessive water is appropriately drained.

As mentioned, since ill water drainage is improved, as shown in FIG. 2, it is possible to construct the surface of the pavement of the road flatly by laying the asphalt mixture (b) as being the surface layer material on the surface layer part 11 flat without a cross slope from a center 11 a in the width direction of the road to each end 11 b. More specifically, for a conventional pavement body 31 of a road as shown in FIG. 7 since it is considered that water is not allowed to enter into the roadbed (A), an oil-based film is formed between the pavement body 31 and the roadbed (A) to block water penetration and a cross slope of a downward-sloping of about 2% is arranged from a center 31 a in the width direction of the road to an area (m) near an end part 31 b and a cross slope of a downward-sloping of about 5% is arranged in a side strip part (n) and the side strip part (n) is constructed by a concrete town ditch (D) having a side ditch and the water is discharged from the discharge facility (F) to a sewage piping (F). An opposite side of the center 31 a has an inverse draft. As a result, there are problems such that rainwater gathers near the side strip part (n) and bicycles or two-wheel vehicles running on the side strip part (n) are forced to experience a dangerous state due to shortage of drainage capacity. Contrary, with the arrangement shown in FIG. 2, since the base course 1 a is superior in water penetration, any part of the surface layer part 11 absorbs the water and any part penetrates the water. Then, it is possible to discharge the water by means of a porous pipe 14 or a discharge drain without running over the drainage capacity, even though no town ditch (D) is arranged at the side strip part (n) of the surface layer part 11 as shown in FIG. 7. As a result, rainfall never gathers near the side strip part (n) and it is possible to effectively prevent a risk for bicycles or two-wheel vehicles running on the side strip part (n). In FIG. 7, a code 101 indicates a sidewalk paved with the asphalt mixture, and a code 102 indicates a concrete partition that pegs out an edge part of the sidewalk 101.

In addition, since the above-mentioned pavement body 1 uses the clinker ash as the porous material, it is possible to obtain the material without any cost or at a low price and to contribute to the ecology largely by recycling the industrial waste.

In case of FIG. 2, the surface of the road pavement may be formed with a certain cross slope (for example, about 2%) from the center lie toward a direction in the width direction of the surface layer part 11 having the water permeable function to one end part 11 b and from the center 11 a to the other end part 11 b respectively. As mentioned, if the gradient is constant and gentle, it is possible to alleviate gathering of the rainfall to the side strip part (n). In addition, it is possible to effectively prevent traffic disturbances for bicycles or two-wheel vehicles running on the side strip part (n) and to effectively discharge the water on the surface of the surface layer part 11 as much as reasonably.

The road to which the above-mentioned arrangement is applied is not only a roadway where vehicles run but also a sideway.

Second Embodiment

The pavement body 2 shown in FIG. 3 has the same water absorption function and water permeable function as that of the base course 1 a of the above-mentioned embodiment in a point that the middle layer part 22 is formed by laying the porous aggregate mixture (a) and the water permeable asphalt mixture (b) as being the surface layer material having the water permeable function is laid on the middle layer part 22 so as to form the surface layer part 21. In this embodiment, a base course 2 a is formed further with a second middle layer part 23 that is formed underneath the middle layer part 22 comprising the porous aggregate mixture (a) by arranging a crushed stone base course (c), and a base layer part 24 that is formed underneath the second middle layer part 23 by arranging a porous material (d) without containing a mixture. The porous aggregate mixture (a) is used by tightly hardening a mixture of the clinker ash and the solidification material of the cement system, the surface layer material (b) is the water permeable asphalt mixture. The crushed stone base course (c) is made of a mixture of the cement concrete and the crushed stones with a mixing ratio of 1:1. The porous material (d) without containing a mixture is a particle body of the clinker ash itself.

As shown in FIG. 3, a thickness of the middle layer part 22 comprising the porous aggregate mixture is designed to be within a range between 100 mm and 300 mm, thinner than a thickness of the middle layer part 12 shown in FIG. 1, and a thickness of the surface layer part 21 is designed to be within a range between 40 mm and 50 mm, thicker than a thickness of the surface layer part 11 shown in FIG. 1 so that a total thickness becomes generally the same as that of the base course 1 a in FIG. 1. The base layer part 24 comprising porous material (d) without containing a mixture is designed to be thicker than any other layer part, for example, about 300 mm. The roadbed (A) is preliminarily excavated in depth (about 300 mm) comparable to the thickness of the base layer part 24 prior to laying the base layer part 24. As a result, it is effective especially for a case of constructing a new road.

Also in this case, as a preferable embodiment, it has been verified by an experiment that it is extremely effective to use a particle size of the clinker ash as being the main material smaller than or equal to 20 mm (in this regard, the particle size of 0.074 mm or smaller occupies less than or equal to 5% of the total), a mixing ratio (a dry soil weight ratio) of the porous aggregate mixture (a) is the clinker ash as being the main material:the solidification material of the cement system=1:0.07˜0.2, and the fresh water 0.18˜0.25 and the additive (150˜200/1 dilution) are added to the porous aggregate mixture (a).

With this arrangement, since the base layer part 24 adjusts the water containing ratio of the soil of the roadbed (A), it prevents the roadbed (A) from absorbing a large amount of water rapidly. Then, it is possible to effectively alleviate a worried “remixing” phenomenon that the roadbed (A) becomes muddy due to vibration from the surface layer part 21 in a state that the rainfall penetrating into the deepest part of the base layer part 24 enters the roadbed (A). Since the base course 2 a is supported by the crushed stone base course (c), it is possible to effectively form the base layer part 24 comprising the porous material (d) at the above-mentioned deepest part with keeping the water permeability and strength.

(Other Applied Example 1 of the Pavement Body of this Invention)

The pavement body 4 shown in FIG. 4 is an example to which the present claimed invention is applied in order to form a base course of a parking lot. The pavement body 4 is so arranged that a base course 4 a having a water absorbing property and water permeable property is formed by a base layer part 43 comprising a crushed stone base course (c), a middle layer part 42 comprising a porous aggregate mixture (a) made by at least mixing clinker ash as being a porous material and a solidification material of a cement system formed on the base layer part 43, and a surface layer part 41 comprising a surface layer material (b) having the water permeable function formed on the middle layer part 42 so as to penetrate surplus water into a discharge channel 44 exiting between the base course 4 a and the roadbed (A) underneath of the base course 4 a and to introduce the water into a water tank (G).

In an ordinary parking lot, the rainfall passes a discharge channel in the parking lot due to a yard drain and is treated in an outside (public sewerage). If the pavement body 4 is used for this kind of the parking lot, since the pavement body 4 is superior in water permeability and water holding property, if a water tank (G) as mentioned above is arranged under the parking lot and the surplus water is stored in the water tank (G) without being discharged into the sewerage, it is possible to reuse the water stored in the water tank (G) for toilet in a store or for sprinkling water for plants. It is necessary that a size of the water tank (G) stores at least more than or equal to 80% of the present capacity to the sewerage. As a facility, it is preferable that a water spraying cock is arranged at an appropriate position in the parking lot and the water stored in the water tank (G) can be sprinkled to the pavement body 4 during summer when the temperature is high and transpiration of water is strong. In case of a parking lot in a large leisure facility or in a shopping mall, it is possible to alleviate a heat island phenomenon by lowering a surface temperature of the surface layer part 41 that has a broad area, and it is also possible to save resources by reusing the rainfall stored in the water tank (G) and to prevent a disaster at a time of heavy rain.

(Other Applied Example 2 of the Pavement Body of this Invention)

The pavement body 5 shown in FIG. 5 shows an example of this invention applied to a platform for electric trains. The pavement body 5 is so arranged that a middle layer part 52 is formed by laying a porous aggregate mixture (a) using a clinker ash on an existing roadbed A′ and a surface layer part 51 is formed on the middle layer part 52 by laying water permeable plate blocks (b′) as a surface layer material. With this arrangement, a base course 5 a having water absorbing property and water permeable property is formed. Since the existing roadbed A′ overhangs a base part (Z) locating under the existing roadbed A′, the surplus water penetrating the base course 5 a is discharged from the overhanging part to the downward.

A temperature on the platform for electric trains rises during summer due to the outside air temperature or influence from thermal storage in a train body, even though the direct sun light is shut out on the platform. However, if the platform is made of the pavement body 5 having the water holding property and the water permeable property, it is possible to restrain temperature rise in a surrounding area.

The platform locates outdoor, however there is a roof over the platform. Then the platform is not likely exposed to the direct sun light and rainfall. However, it is difficult to restrain the temperature rise on the platform because the roof exposed to the sun light stores heat or the train itself possesses heat during summer. Then if the platform as being underfoot is made of the pavement body 5 having superior water holding property and water permeable property, as shown in FIG. 5, it is possible to restrain the temperature rise in whole of the platform by making use of a characteristic that the vaporization heat deprives ambient temperature at a time when the heat of the surface layer part 51 evaporates the water held in the pavement body 5.

In this case, as a preferable embodiment, it is extremely effective to use a particle size of the clinker ash as being the main material smaller than or equal to 20 mm (in this regard, the particle size of 0.074 mm or smaller occupies less than or equal to 5% of the total), a mixing ratio (a dry soil weight ratio) of the porous aggregate mixture (a) is the clinker ash as being the main material:the solidification material of the cement system=1:0.10˜0.20, and the fresh water 0.18˜0.25 and the additive (150˜200/1 dilution) are added to the porous aggregate mixture (a).

(Other Applied Example of the Porous Aggregate Mixture Used for this Invention)

In case of constructing a large-scaled concrete structure (X) such as the above-mentioned discharge facility (C), (E) or the water tank (G), it is effective to form a mold form 200 by using the porous aggregate mixture (a) as shown in FIG. 6.

More specifically, in case of forming a building frame such as the concrete structure (X), ordinarily there is a troublesome procedure such that a slum value of a ready-mixed concrete has to be measured. In addition, if the slump value is big, it is not possible to keep a sufficient strength of the concrete structure (X). Furthermore, ordinarily since the mold form is made of wood, its wood chip might be mixed into the concrete structure (X) so as to influence on the strength of the concrete structure (X). Then, similar to the above-mentioned embodiment, the porous aggregate mixture (a) is made by mixing and kneading the solidification material of the cement system into the clinker ash as being the porous material and an additive and fresh water are mixed and kneaded so as to be formed into a plate shape having a thickness of 30˜50 mm. This is used for the mold form 200 for the concrete structure (X) and after concrete is casted inside of the mold form 200, only a mine timbering 300 is dismounted. And then, the mold form 200 and the casted concrete are backfilled.

In this case, as a preferable embodiment, it has been verified by an experiment that it is extremely effective to use a particle size of the clinker ash of 0.074 mm˜25 mm, a mixing ratio (a dry soil weight ratio) of the porous aggregate mixture (a) is the clinker ash as being the main material:the solidification material of the cement system=1:0.15˜0.25, the fresh water 0.18˜0.25 and the additive (150˜200/1 dilution) are added to the porous aggregate mixture (a), and then a load (more than or equal to 1000 Kg) is applied so as to form the mold form 200.

The mold form 200 has both the superior water permeable property and the superior water absorbing property, and the surplus water generating during casting the ready-mixed concrete is discharged outside and the water necessary for hardening the concrete is kept inside of the mold form 200 by means of the water holding property and the water is supplied to inside of the concrete gradually in accordance with a reaction heat at a time when the concrete is hardened. With this property, it is possible to secure the hardness of the concrete structure (X). In addition, it is difficult to treat the bleeding water as being the strong alkali water such that the blooding water requires to be neutralized with sulfuric acid at a time of casting the concrete, however, if most part of the bleeding water is confined to inside of the mold form 200, it is possible to dissolve this concern.

In case that a wooden panel is used for a mold form, dust might generate and the dust might be mixed into inside of the structure at a time of casting the concrete so that the strength of the structure might be influenced. If the above-mentioned mold form is used, it is possible to prevent the dust from mixing into the concrete.

In addition, with this arrangement, since it is easy to process the mold form 200 while its strength is kept, it is possible to improve the working efficiency.

The slump of the ready-mixed concrete is ordinarily about 8, however, it is possible to set the viscosity of the ready-mixed concrete at about 12 or over. With this arrangement, liquidity of the ready-mixed concrete is improved so that the working efficiency in casting the ready-mixed concrete is improved largely. Since the bleeding water is filled in the panel, it is possible to prevent the junker (rock pocket) that generates at a time when the ready-mixed concrete of high viscosity is casted.

Some embodiments of this invention are explained, however, each concrete arrangement is not limited to the above-mentioned embodiments and may be variously modified without departing from a spirit of the invention. For example, instead of the clinker ash, the porous material can be substituted by a material having the water permeable property, the water holding property and the strength.

Possible Applications in Industry

As mentioned, in accordance with this invention, since the pavement body is made of the material having both the water holding property and the water permeable property so that it is possible to soak the water through the roadbed appropriately in addition to keep the water, the water is kept and soaked up at a dried time and furthermore in a case that no water is supplied to the roadbed during a long period such as drought, the water is soaked up and it is possible to deter the temperature rise on the surface layer. In addition, since the water can be absorbed at any place on the asphalt locating at the surface layer, and the water is kept at any place, it is possible to realize a well drained arrangement without forming puddles and there will be no case that a large amount of water flows into a drain at once at a time of torrential rain. Then it is possible to provide the pavement body that prevents a large amount of water from flowing in a drainage pipe. 

1. A pavement body characterized by comprising at least two layers, wherein a porous aggregate mixture made by mixing a porous material with a solidification material of a cement system is laid and a surface layer material having a water permeable function is laid on the porous aggregate mixture.
 2. The pavement body described in claim 1, wherein a semi impermeable film having both the water permeable function and a blocking function is formed at a boundary between the porous aggregate mixture and a roadbed locating under the porous aggregate mixture.
 3. The pavement body described in claim 2, wherein the semi impermeable film is inclined in a direction of a drain.
 4. The pavement body described in claim 1, wherein a surface of a road pavement is formed by laying the surface layer material in a flat state from one end part in a width direction to the other end part without any cross slope from a center to each end in the width direction.
 5. The pavement body described in claim 1, wherein a surface of a road pavement is formed with the surface layer material having the water permeable function inclined from a center to one end part toward a width direction and the center to the other end part by a certain cross slope respectively.
 6. The pavement body described in claim 1, wherein a crushed stone base course is laid underneath the porous aggregate mixture made by mixing the porous material with the solidification material of the cement system, and furthermore a porous material without including a mixture such as a solidification material is laid underneath the crushed stone base course.
 7. The pavement body described in claim 1, wherein the porous material is clinker ash.
 8. A method for constructing the pavement body described in claim 1, and characterized by that a current pavement is taken away so as to expose a roadbed, a middle layer part comprising the porous aggregate mixture is constructed, and a surface layer part comprising the surface layer material having the water permeable function is constructed sequentially.
 9. A method for constructing the pavement body described in claim 6, and characterized by constructing a base layer part comprising a porous material without including the mixture such as a solidification material, a second middle layer part comprising the crushed stone base course, a middle layer part comprising the porous aggregate mixture, and the surface layer part comprising a surface layer material having the water permeable function sequentially from a bottom to a top.
 10. A mold form for concrete that can be backfilled and that is a porous aggregate mixture made by mixing a porous material with a solidification material of a cement system molded into a plate shape, and inside of which concrete is casted and that is backfilled as a part of a concrete structure.
 11. A pavement body characterized by that a middle layer part is formed by laying a porous aggregate mixture made by mixing a porous material with a solidification material of a cement system on a concrete floor slab overhanging from a base part, and a surface layer part is formed by laying a surface layer material on the middle layer part so that a base course having a water absorbing property and a water permeable property is formed on a platform of a train. 